404 LOWER VERTEBRATES. 



coasts of New Jersey ami jVlahania, as well as the " Western Sea." It contains the 

 most elongate forms of the order, though tliey do not reach sucli a size as do some of 

 the Ziiodons. The quadrate bone gives evidence that there was considerable lateral 

 flexure of the mandibular rami ; and that tlie animals were strong and muscular is 

 shown by the striations and sculj)tures still ajipeai-ing on many of the bones. Tliat 

 tlie vertebral column might not be dislocated by the animal's powerful contortions, the 

 vertebras are provided with an extra pair of articular processes which are very charac- 

 teristic. The largest representative is C. cineriarum, from the Kansas strata, and 

 reaches a length of forty feet. C. tortor was a lithe and active animal, with numerous 

 knife-like teeth, and probably fed on fish. C. inmiilus is remarkable for its small size, 

 being only about twelve feet in length. It was probably not infrequently the unfor- 

 tunate prey of some of the larger cretaceous sharks. 



The genus Platecarpus is also represented by about a dozen sjiecies which resemble 

 Clidastes in the form of the humerus, tlumgh the vertebral articulations are like 

 those of Liodon. The muzzle is considerably shorter than in the i^revious genus, 

 from which the animals also differ in having the chevron-bones free from the vertebral 

 centra. The teeth are very characteristic, being neither compressed like Liodon, nor 

 angularly faceted as in Mosasawus but are curved and, in section, sub-circular. 

 Such sjsecimens as have been discovered have been of medium size. 



Fig. 234. — Skeleton of Clitlastes, restored. 



Mbsasaiirus has been .abundantly found iu the greensand of Xew Jersey, and other 

 cretaceous localities further south. It differed from the two previous genera in having 

 the flippers more pedunculate, the humerus and femur being more slender, and in 

 having the teeth provided Avith facets. The chevron-bones are in part coossified, and 

 the arches of the vertebral column interlock, presenting in rudiment, the articular 

 processes of Clidastes. The representatives of this genus, of which there were in 

 Europe two, and in America, where the animals were much more abundant, nearly a 

 dozen species were, like other Pythonomorphs, long and slender, and with a flattened, 

 pointed head. The food, which was captured alive, was quickly swallowed, passing, 

 on its way to the loose pouch-like gullet, between the expanded branches of the lower 

 jaw. M. maximus was the largest species, and sometimes reached a length of eighty 

 feet. 



The genus Liodon has the teeth compressed, lenticular in sectional outline, and 

 formed for cutting. The vertebraj have not the strong articular processes of Vlida.^tes 

 and the humerus is small and narrow. The typical species of the genus was described 

 by Owen from remains found in the English chalk, and is extremely rare. In America 

 the forms abounded during the chalk iieriod and were tlie giants of the order. L. 

 proriger, of the Kansas beds, measured seventy-five feet in length, and was provided 

 with a long projecting muzzle, a development possibly used as a ram when fighting. 

 L. dysj)elor was probably the largest of known reptiles, considerably exceeding the 

 3fosasaurus maximus in size. The source of the food supply of such monsters may 

 well excite our curiosity, as their magnitude does our surprise. 



